Update ubuntu build to 3.1

What is your Merge about?

If this is your first merge, please use the Initialization Template.

Updating the Ubuntu based build to 3.1 as well now that Debian based is merged

For more information please visit Iron Bank Documentation

Note: Please be sure you create an issue related to this merge request and the issue is labeled StatusReview, this will initiate a CHT member review of your merge request.